This invention relates to a vacuum insulating glass (IG) unit, and a method of making the same. More particularly, this invention relates to a vacuum IG unit including a glass fiber inclusive edge seal.
Vacuum IG units are known in the art. For example, see U.S. Pat. Nos. 5,664,395, 5,657,607, 5,891,536 and 5,902,652, the disclosures of which are all hereby incorporated herein by reference.
Prior art FIGS. 1-2 illustrate a conventional vacuum IG unit. IG unit 1 includes two spaced apart sheets of glass 2 and 3 which enclose an evacuated or low pressure space 6 therebetween. Glass sheets 2 and 3 are interconnected by peripheral or edge seal of fused solder glass 4 and an array of support pillars or spacers 5.
Pump out tube 8 is sealed by solder glass 9 to an aperture or hole 10 which passes from an interior surface of glass sheet 2 to the bottom of recess 11. A vacuum is attached to tube 8 so that the cavity between sheets 2 and 3 can be evacuated to create a low pressure area 6 between the opposing glass substrates. After evacuation, tube 8 is melted to seal the vacuum. Recess 11 retains melted and sealed tube 8. Chemical getter 12 may be included within machined recess 13.
Edge seal 4 is often made from solder glass in conventional vacuum IG units. For example, see U.S. Pat. No. 5,902,652. As explained in the ""652 patent, the solder glass edge seal is formed by depositing the solder glass as a liquid slurry onto the surface of one or both of the glass sheets 2, 3. The sheets are brought together and the entire unit is then heated to a temperature at which the solder glass melts, wets the surface of the glass sheets, and flows to produce a hermetic seal 4 between the sheets 2 and 3. While solder glass edge seals work well, they may be viewed by some as disadvantageous in that the aforesaid slurry is required during the manufacturing process, which may tend to be somewhat messy in certain circumstances.
It is also known to use indium inclusive edge seals 4. Unfortunately, the use of indium may tend to cause the edge seal 4 to be undesirably weak from a mechanical perspective in certain instances. Additionally, indium tends to be rather expensive and is undesirable for this reason as well.
It is apparent from the above that there exists a need in the art for a vacuum IG unit, and corresponding method of making the same, including an improved edge seal between opposing glass sheets or substrates. There also exists a need in the art for a fiber inclusive edge seal for use in vacuum IG window units.
This invention will now be described with respect to certain embodiments thereof, accompanied by certain illustrations.
An object of this invention is to provide a vacuum insulating glass (IG) unit including a glass fiber inclusive edge seal. The edge seal may include one or more glass fibers in certain embodiments of this invention. For example, in one embodiment a single fiber may be used to form the edge seal with the fiber""s opposing ends being fused (or otherwise attached) together at an interface or junction in order to complete the hermetic edge seal. In another embodiment, a plurality of elongated glass fibers may be bundled together, with respective ends of the bundle being fused together at an interface or junction in order to complete the edge seal. In still further embodiments, a plurality of glass fibers may be aligned with one another in series to form the edge seal, with ends of adjacent fibers being fused (or otherwise attached) to one another to complete the edge seal.
Another object of this invention is to provide a vacuum IG window unit including one or more elongated glass fiber spacers for use in an edge seal of the IG window unit.
Another object of this invention is to provide a vacuum IG window unit including a glass fiber inclusive edge seal having an index of refraction approximately the same as (i.e. within about 15% of) the index of refraction of at least one of the glass substrates.
Another object of this invention is to fulfill one or more of the above-listed objects.
Generally speaking, this invention fulfills one or more of the above described objects and/or needs by providing a thermally insulating glass panel comprising:
first and second spaced apart glass substrates defining a low pressure space therebetween having a pressure less than atmospheric pressure;
a plurality of spacers disposed between said first and second glass substrates in order to space the substrates from one another; and
at least one elongated fiber inclusive hermetic edge seal disposed at least partially between said first and second glass substrates for hermetically sealing said low pressure space.
This invention further fulfills one or more of the above-listed objects and/or needs in the art by providing a vacuum IG window unit comprising:
first and second spaced apart substrates having a low pressure space therebetween with a pressure less than atmospheric pressure;
a plurality of spacers disposed between said first and second substrates for spacing said substrates from one another; and
an edge seal including at least one elongated fiber disposed between said first and second substrates for sealing said low pressure space.
This invention still further fulfills one or more of the above-listed objects and/or needs by providing a method of making a vacuum insulating glass (IG) window unit, the method comprising:
providing first and second glass substrates;
positioning a plurality spacers on the first substrate;
positioning at least one elongated glass fiber on the first substrate at least partially at an edge seal location;
sandwiching the at least one elongated glass fiber and the spacers between the first and second glass substrates;
heating at least an edge seal area so as to form an edge seal including the at least one elongated glass fiber; and
evacuating a space between the first and second substrates so that the space has a pressure less than atmospheric pressure.